Coffee maker



May 17, 1949. R. L. sMrrH 4GOFFEE MAKER Filed June 4, 1945 Patented May 17, 1949 CQFFEE` MAKER 'Roland L.l small, Belmont, Mass., signor to Nuproducts Corporation, Cambridge, Mass., a corporation of Massachusetts Application June 41945, serial No.-597,51s

'I'his linvention relates to coifee makers and preferably to a coffee maker of the vso--called vacf uum type in which the pressure of boilingwater in a lower heating vessel automatically compels the water to flow therefrom into an upper in'- fusion vessel for infusion-with 4a predetermined charge -of ground coffee contained therein, and vacuum automatically compels the infusion of hliquid coffee to return to the lower vessel when the heating of the lower vessel is discontinued z Claims. wl. sel-292)' q 2 ally builds up.' However, considerable portions of f the. coffee grounds pass'through or yaround the and the pressure therein drops below the point l required to drive the Water into the upper vessel.

In a common form of vacuum coffee maker on the market, the lower vessel. has anfopen mouth into which is telescopically fitted an upper vessel enlarged portion before ythe .device finally clogs sufficiently to act as an effective screen, and in Y 'any case, neither of Ithese constructions seems to fil-ter the coffee as eiciently as a cloth filter.

In all forms where a coiled spring is used, the

Ivinner surfaces of the spring soon become fouled with old coffee residue which is not only difficult yto get at; in order to remove, but if not removed may affect the taste of the coffee. Moreover, the-metallic parts used to hold the strainer in place are apt to react with the chemeq-uipped with a packing ring. The upper vessel is provided with a narrow tubular extension de pending into the lower vesseland terminating a short distance above the bottom thereof. The upper end of the tubular extension is covered 'by a strainer disc of cloth which, due to its lack of mechanical strength, has to be heldin shape by tying it at its edge around a perforated porcelain disc seating over the upper end of the tube. The entire strainer unit is itself held in place by means of a coiled spring anchored at its upper end to` the porcelain disc and extending downwardly into the tube and provided at its lower end with a hook and a short chain to be grasped bythe fingers for the purpose of stretching the spring -far enough to permit the hook to be anchored under the lower edge of the tube.

In an alternative form of strainer, the 'clot disc is held in place by a coiled or plain wire ex-g pansion ring.

Both types of strainer are open to the objection that either a poor fit against the glassis formed or numerous folds are formed in the cloth permitting portions of the more finely divided coiee grounds and sediment to by-pass the strainer and descend into the lower vessel instead of being caught by the mesh lof the cloth.

Both types are also open to the objection that vthe cloth is diiiicult to remove and clean, due to the tendency of the drawstring to catch in the coils of the spring. Moreover, the porcelain disc ical constituents of the coffee to produce salts which impart anunnatural taste or flavor to the coffee. l' i My invention retains the cloth type of lter in an improved form while obviating the aforementioned and other objectionable features of the prior art. My lteris not only more efficient to use, but less expensive to manufacture, doing away entirely with lboth the porcelain disc and the metal spring and its extension.

In my construction a coffee reservoir with a removable porous bottom is provided. This reservoir is provided with means for measuring the ground coffee asi 'it is poured directly into it from its origin-al container.

The advantages are many:

1. There is no longer any danger of the oo 'ee grounds by-passing the lter and settling into the lower vessel, nor chance of trouble, due to folds collects coffee residue in its perforations and on the unglazed surfaces of the disc.

In other forms of coffee maker,` the illter cloth y is omitted and a glass rod provided with an enlarged portion is inserted in the tube and seated either-by gravity or by a coil spring hooked under the lower edge of the tube. The enlarged portion is covered with a Toughened surface on which a filtering layer of coffee grounds eventu- ,surface of the cloth filter is utilized instead of merely a small number of perfor-ations, asin the case of the porcelain disc or glass rod, thereby enabling a much finer grind of coiiee to be used.

2. The cloth strainer may be attached or detached in a few seconds, since only a single draw-l string protrudes from the edge of the cloth strainer and there' is no need to tie the drawstring nor to provide the cloth strainer with an elastic retaining element, as has sometimes been done.

3'. The coffee ground reservoir is located within the lower vessel but is integral with the upper vessel.' y llhe open top of the upper vessel serves as a funnel toA guide the coffee, without the usual ldanger of spilling it around. Moreover, my coffee reservoir is a self-contained measuring means.

thereby-avoidingl the necessity for using a sepav indiciaV may refer to the number of cups of liquid coil'ee to bemmade orv they may refer tothe number of tablespoonfuls of ground coee to be` placed in the coffee reservoir.

' p 4 .The bottom of vessel a central opening I4 and a depending coffee res- 4. The upper-vessel', upon being removedfrom 5 the lower container after use, will stand upright upon its flanged base, so 'there is no longer any need to take great care against having it roll oil? onto the iloor or any need to'provide, as some ervoir lextension I5. The lower end of extension I5 is disposed near the bottom' of the interior o! water-heating vesse1 Iliand is provided with an extern'al annular radial flange I6 which serves as a means for, holding in position a strainer disc g I1 made from foraminous'sheet material such manufacturers do, a special stand forholding it upright.

5. All interior-parts of my coee maker which.

are exposedto the reaction of the conce, except the cloth strainer, are non-metallic, being preferably made of glass orother ceramic or rei'rac tory material which is inert to the coil'ee. and

hence will not/impart Aan" unnatural taste or\ flavor thereto. i f V 6. My coiee maker comprises a minimum number of workingparts andthese may be as cloth, for example.

-. Strainer I1 has its marginal portion folded inf I wardly and secured in that position by a line of I.stitches I8 so as to provide a tubular hem I9 inlclosing a drawstring 20. The strainer is applied to the lower end of the;n coffee reservoir I5 with its hem above the flange I6 so that said hem is contracted and drawn into position above 'said flange 'by the drawstring, thereby fastening the strainer securely in position across the openend quickly and easily assembled and disassembledl for purposes of cleaning or sterilizing the surfaces thereof which come into cdntact with the coffee.

Other advantages will appear as this descripa removable porous bottom. The lower ,end of the coffee reservoir is disposed near the bottom of the interior of the water-heating vessel and is anged to have removably secured thereto a removable strainer element.of foraminous sheet material. `'Ihe strainer closes the bottom of the coiee reservoir, and also serves to prevent the 'of the coffee reservoir.

One end of the drawstring'is fastened to a bead or its'equivalentl 20! and the other` endof the string is passed thrdugh the bead and made long enough to be anchored in adjacent slits Ill cut in the marginal edge of the yring II at a plurality of spaced points. I may however fasten the ends of the drawstring in other'manners. The chime at the top of vesse1 I0 is flared outwardly as at 2| to provide an annular channel or recess 22 upon the exterior of the vesse1 adjacent to.the top thereof for the reception vof an encircling band 23. whose opposite ends are bolted to the opposite sides of ahandle 24.

`In using the above-described coffee maker a measured amount of water is poured into vessel I0 and a measured amount of ground coffee Y is placed within the coiee reservoir as indicated at 25 where it is supported bythe strainer'lT.

y'Ihen the vessel I2 with packing ring II mountpassage of coifee grounds and sediment into the lower vessel at the'l conclusion of the infusion period.

In order to reliably hold the strainer in-.operative position while yet enabling it to be readily removed when required, I fasten ne end of its drawstring to a bead or equivalent fastening device and extend the other end of said string for a distance suilicient to permit it to be carried up to the sealing ring and anchored thereto.

Other features of my invention are hereinafter pointed out.

In the accompanying drawing wherein I haveA illustrated a preferred vention:

Figure 1 is a vertical section through my improved coffee maker, the sealing ring being shown slightly raised for clarity of illustration.

Figure 2 is a section on line 2-2 of Fig. 1.

Figure 3 is a side elevation of the infusion vessel and associated parts, removed from the assembly, and

Figure 4 is a plan view of a strainer suitable for use as part of my improved coifee maker.

The illustrated embodiment of my invention comprises a lower water-'heating vessel I0 of glass or other ceramic or refractory material. /Vessel I0 has an opening at its top into which is telescopically fitted an upper infusion vessel I2 equipped with a packing ring II of rubber or other suitable resilient material. Vessel `I2 is also of glass or other ceramic or refractory material and has at its top an opening that is normally closed by a removable lid or cover I3.

embodiment of my inupon strainer I 1.

ed thereon is telescopically tted into the vessel I0 .so as to occupy the position shown in Fig.

1. Heat is now applied to vessel IIJ and steam is generated therein. This forces the water upwardly through coffee reservoir I5 and into vesse1 I2 carrying the ground coffee with it. vWhen the heating of vesse1 I0 is discontinued and said vessel is permitted to cool the steam within the same is condensed and atmospheric pressure forces the vinfusion downwardly from vessel I2 through strainer I1 and into vessel I0, the infusion carrying the coffee grounds with it back into coee reservoir I5 where it is deposited The vacuum produced within vessel I0 causes al1 of the infusion from extension I5 into vessel III. The strainerv eiectually preventing the passage of sediment or cofl'ee grounds into vessel III during the downward movement of the infusion.

If desired, the exterior of -the coffee reservoir I5 may be provided with a series of graduations 26 for use in measuring the ground colIee as it is poured therein from its original container.

The coffee reservoir I5 has been shownas of somewhat globular shape, but may be straight or tapered if desired, or otherwise shaped.

.While I have shown and described a preferred embodiment of my invention and have suggested certain possible modifications, I recognize that still other changes in construction, design, and material may be made as occasion demands. All such are therefore to be regarded as within the purview of my invention the appended claims.

Although I have illustrated a vacuum type coffeemaker, it will be understood that the l2 is shaped to providel the downward discharge of if within the scope of are applicable to other about the infusion vessel between the two reservoirs for supporting the 'infusion vessel on and with its tubular reservoir depending into the lower vessel, a flexible iiiter over the bottom end of the infusion vessel. a drow string for maintaining the ilter in place on the vessel, and means carried by the ring for receiving and anchoring the draw string. v

2. The combination dened in claim 1 in which one end of the draw string passes through an eye carried by the other end of the draw string, pulling on said one end of the draw-string being adapted to constrict the iiiter onto the vessel. I

o .nd seid means carried by the ringbeing eds to receive and anchor said one end of the draw string.

ROLAND L. SMITH.

REFERENCES CITED The following references are of record in the nie of this patent:

UNITED STATES PATENTS Number Name Date 129,882 Behringer July 31, 1872 782,956 Ferguson Feb. 21, 1905 1,983,142 Moriys, Dec. 4, 1934 2,224,378 Coniglio Dec. 10, 1940 2,386,532 Wolcott Oct. 9, 1945 FOREIGN PATENTS Number Country Date 10,485 Greet Britain 1888 

